CurtPalme.com Home Theater Forum

[DGP]

I’m facing a estrange issue with my projector, only in one tube (green). The projector is quite new, from 2004 and has less than 600 hours of use.

I detected that the green tube is always showing a bit of light, even if I use a 0 IRE pattern. I’m not able to turn it completely off by lowering G2 (49 drive 90) or Brightness (50).

Things I already did:

Replace the VNB.
Replace the HDM.
Replace the VIM.
Replace the HV Splitter.
Unplug convergence focus and Stig coils.
Swap video inputs cables from one VNB to the other (Red - Green)

The problem is still there.

Also when I turn the projector off, there is a kind of beam issue, but is not strong enough the burn the tube surface (is almost not visible on screen). The green tube is a P43 type.

Please take a look to the attached video.

Test condition:

0 IRE pattern
Blue and Red tubes are completely dark and green shows a kind of bumping light (not visible on screen) a little bit bigger than the raster size.

Any idea?

Thanks,
DGP

[Curt Palme]

Your green tube is bad, it has contamination in the electron gun, causing the flickering and the dot. Frankly, I'd live with it, but if you want to get rid of the light output, you need to change the tube.

[Curt Palme]

Your green tube is bad, it has contamination in the electron gun, causing the flickering and the dot. Frankly, I'd live with it, but if you want to get rid of the light output, you need to change the tube.

[DGP]

[Nashou66]

Try to tap the neck of the green tube while its on. I used a wooden 10cm dowel tapping the neck with the cpc magnets off so i could tap up and down the neck
in that area, do not knock too hard. If it is contamination you'll see a light show inside the tube neck as the contamination burns away, like a small aurora borealis.

Nashou

[DGP]

[CIR Engineering]

[Nashou66]

Yes like Craig says, I just like to remove the cpc magnets to be able to see if the tapping of the glass is working or not, you will hear it for sue but some of the final contamination doesn't make a sound but creates a plasma show in the tube neck.

Athanasios

[DGP]

Thanks for your replies. I will do now and see what happen.

Thanks again,
Diego

[DGP]

So I did it already and nothing changed. I don’t know if applied the right strength or not long enough, but the picture on screen shakes a little.

I attached a video how I did it.

First time I did this the room was completely dark, just to be able to see if something happen inside the neck.


Thanks,
Diego

[Curt Palme]

Just leave it. If you can't see the light on the screen, you should be fine. The dot isn't near strong enough to burn the phosphor, and you might find that the problem goes away after a while.

I had a 1209s here last night that flickered badly on the red, noticeable on the screen. I ran the set overnight, and this morning it's perfect. THe set was fine when I put it into storage 6 months ago, so I figured the problem would go away overnight, and it did.

[Curt Palme]

Just leave it. If you can't see the light on the screen, you should be fine. The dot isn't near strong enough to burn the phosphor, and you might find that the problem goes away after a while.

I had a 1209s here last night that flickered badly on the red, noticeable on the screen. I ran the set overnight, and this morning it's perfect. THe set was fine when I put it into storage 6 months ago, so I figured the problem would go away overnight, and it did.

[1031]

[Ile]

Phillips test pattern generator have flashing feature.
http://wareseeker.com/download/phillips-pattern-generator-3.11.rar/304089

You can flash black and green screen with 2 sec intervals. You can move and resize flashing window to fill whole screen.

It could take several hours to get crap burned.

Or just use projector normally...

[CIR Engineering]

[DGP]

I will try with the run in cycle, only flashing a green screen, expanding the raster and defocusing at max. I will leave it some hours, but I want to be around during the run in cycle, just in case the flashing stops for whatever reason, to avoid a nice menu mask on the tube surface.

Thanks for all your replies,
Diego

[vespaman]

[DGP]

[antorsae]

You gotta love when that happens!